Russian MFSK-17 125Bd/125Hz burst system (selcall waveform?)

The waveform-1 seems to have some LMF components and a curious tones format (Fig. 3) maybe used to wake-up receiving modems or matching a certain known tone-sequence. Waveform-1 is then followed by a Russian male operator calling the other station: "first calling twentieth" (thanks my friend KarapuZ who translated the voice comm).

Fig. 3

Bursts have a duration of ~1080 msec and sent each 4000msec in waveform-2.

The same signal, more precisely the here-termed waveform-1, was reported about one year ago in radioscanner.ru forum. "Sometimes a multi-frequency transmission with spreading has been observed" my friend KarapuZ say.